Power mower with riding platform for supporting stand-operator

ABSTRACT

A zero-turning-radius power lawn mower for operation by a standing-occupant includes first and second independently driven and controlled rear drive wheels mounted on separate drive axles. A riding platform for supporting the standing-occupant or operator is located between the first and second rear drive wheels. The rear drive wheels are independently driveable in both the forward and reverse directions at variable speeds so as to allow for substantially zero-radius-turning of the mower about a central turning point. The riding platform is positioned at this turning point so that the standing-occupant remains substantially unaffected by centrifugal force created during approximate zero-radius-turning of the mower thereby allowing the mower to take such turns at higher speeds. Such positioning of the platform also provides for improved maneuverability, reduces the likelihood that the platform will bottom out when the mower goes over bumps, and creates a safer mower less susceptible to tipping due to the resulting low center of gravity. The low center of gravity created by the position of the riding platform for the standing-operator also results in the mower having improved traction and being less likely to pop &#34;wheelies&#34; upon acceleration.

This is a continuation, of application Ser. No. 08/726,927, filed onOct. 3 1996 now abandoned; which is a continuation of 08/615,518, filedon Mar. 11, 1996 U.S. Pat. No. 5,600,944); which is a continuation ofSer. No. 08/357,740, filed on Dec. 16, 1994 (now U.S. Pat. No.5,507,138), each of which is incorporated herein by reference.

This invention relates to a power driven device. More particularly, thisinvention relates to a power lawn mower including a riding platform forsupporting a standing-operator.

BACKGROUND OF THE INVENTION

Conventional hydraulically driven or hydrostatically controlled machinessuch as power lawn mowers include a pair of drive wheels, each of whichis independently operated by a hydraulic or hydrostatic pump coupled tothe mower's engine. A corresponding motor is provided for each drivewheel, each motor being powered by one of the pumps. Each pump includesa control lever for regulating fluid pressure and direction to itscorresponding motor. In such a manner the drive wheels of the powerdevice (e.g. lawn mower) are independently controlled so that each maybe rotated at variable speeds in both forward and reverse directions.

Accordingly, each drive wheel of hydrostatically controlled mowers maybe driven in either the forward or reverse direction and the mower maytherefore be turned through various angles. Hand levers for manipulationby the operator on such mowers are typically provided on handle membersfor moving the individual pump control levers into desired positions.The above described power lawn mowers are commonly referred to aszero-turning-radius mowers because if operated in a particular orpredetermined manner, the right drive wheel and left drive wheel may berotated in opposite directions at similar speeds thereby allowing themower to conduct approximate zero-radius turns about a central pointlocated between the drive wheels. This, of course, provides for improvedmaneuverability in tight environments. Exemplary zero-turning-radiusmowers are disclosed, for example, in U.S. Pat. Nos. 5,077,959;4,967,543; 4,991,382; and 4,920,733.

Conventional power mowers are generally divided into three separatecategories: (i) self-propelled walk-behind mowers; (ii) mowers operatedby a seated occupant; and (iii) mowers operated by a standing-occupant.

U.S. Pat. Nos. 5,077,959; 4,967,543; 4,991,382 and 4,920,733 disclosetypical walk-behind power mowers including hydrostatically orhydraulically controlled rear drive wheels. Unfortunately, the operatorof walk-behind mowers such as these is forced to continually walk duringmowing operations, thereby leading to fatigue. This is, of course, adisadvantage associated with walk-behind mowers, especially in hillyenvironments. As a result of operator fatigue, mowers controlled bywalking operators are generally less productive over extended periods oftime. A further disadvantage of walk-behind mowers is that theoperator's feet are left unprotected and thus exposed to potentiallydangerous flying debris.

Turning now to power mowers operated by seated occupants, U.S. Pat. Nos.3,483,682; 4,487,006; 4,316,356; and 4,998,948 disclose typical suchmowers. Unfortunately, seated occupant operated mowers tend to havefairly high centers of gravity (i.e. they are top heavy) due to theposition of the operator's center of gravity which is far from theground. Such high centers of gravity render mowers operated by seatedoccupants more likely to tip or roll. Because tipping and rolling ismore likely to occur as such mowers operate through turns or on hills,seated operators must be very careful in such environments and work atreduced speed. Operation at reduced speeds clearly leads to reducedproductivity of the mower. Additionally, seated operators have a hardtime ducking under low hanging tree limbs and the like because of thefixed position of the seat and thus the lower half of the operator'sbody. Furthermore, seat assemblies on such mowers necessarily increasethe overall cost of the mowers.

U.S. Pat. Nos. 2,354,576; 3,485,314 and 5,004,251 disclose power devicesoperated by standing-occupants supported on trailers or sulkies. Theoperators of these devices (e.g. power mowers) are supported on sulkydevices or trailers removably attached to the mower. Thus, thestanding-operator supporting trailing platforms of these patents are notactually part of the mower, but rather are mower attachments which mustbe removed or folded up during mower transport. While the trailingplatforms or sulky devices of U.S. Pat. Nos. 2,354,576 and 5,004,251provide for mower operation by a standing-occupant, they greatly extendthe overall length of the mower system and are rather bulky in nature.Thus, the sulky or standing-occupant platforms of these patents must bedisconnected or folded up during transport of the mower. This isextremely burdensome and inconvenient. A further problem with removabletrailing platforms such as those disclosed in U.S. Pat. Nos. 5,004,251and 2,354,576 is that they significantly extend the length of the mowerthereby decreasing maneuverability in tight spaces. Additionally,because these sulky or attachment devices are not actually part of themower, they must often be purchased separately thus increasing theoverall cost of the mower system.

U.S. Pat. No. 4,878,339 discloses a power lawn mower including aselectively deployable riding platform for supporting astanding-operator or occupant. The mower of U.S. Pat. No. 4,878,339 maybe operated either as a walk-behind mower or alternatively as astanding-occupant/operator mower depending upon whether or not thestanding-operator platform is deployed. In other words, because theplatform is selectively deployable it is non-fixedly mounted to themower. Unfortunately, in the walk-behind mode, this mower experiencesthe above-referenced problems associated with typical walk-behindmowers.

In the standing-operator mode (i.e. when the riding platform isdeployed), the power mower of U.S. Pat. No. 4,878,339 experiencesnumerous problems. Firstly, the position of the riding platform behindthe rear drive wheel axis lengthens the overall length of the mower andrenders it difficult to maneuver in tight areas. Furthermore, while theplatform of this patent provides for a fairly low center of gravity, itslocation behind the rear drive wheel axis and extension substantiallybehind the rear drive wheels renders it likely to bottom out or contactthe ground when the mower goes over curbs, bumps, or the like.

If the power mower of U.S. Pat. No. 4,878,339 were operated so as toconduct a substantially zero-radius-turn, the rear drive wheels would beoperated in opposite directions at similar speeds and the centralturning point would be located between the rear wheels along the reardrive wheel axis. Because the standing-occupant platform of the mower ofthe '339 patent is not located at this central turning point (i.e. theplatform is located well behind the rear drive wheel axis in thestanding-operator mode), the operator is adversely affected bycentrifugal force created during approximate zero-radius turns of themower. The standing-operator is also more affected by centrifugal forcecreated during other mower turns. Due to this centrifugal force, thestanding-operator or occupant of the mower of the '339 patent is forcedto take turns at slower speeds thus reducing the overall productivity ofthe mower over extended periods of time.

Another problem with the position of the platform of the U.S. Pat. No.4,878,339 mower is that its location rearward of the rear drive wheelaxis creates a greater tendency for the mower to "pop wheelies" uponacceleration, especially going up hills, because the mower's center ofgravity is moved rearward when it is operated by a standing-occupant.The position of the platform of this patent often necessitates thestanding-operator leaning forward prior to and during acceleration inorder to avoid popping such wheelies and possibly tipping over themower.

It is apparent from the above, that there exists a need in the art for apower lawn mower operable by a standing-occupant including a platformfor supporting the standing-occupant, the platform being positioned onthe mower so as to result in the following advantages: (i) a low mowercenter of gravity resulting in improved drive wheel traction and lesssusceptibility to tipping or rolling; (ii) a lessened overall length ofthe mower so as to render it highly maneuverable in tight spaces andenvironments; (iii) a reduced tendency of the standing-operator platformto bottom out or contact the ground when the mower goes over curbs,bumps, or the like; (iv) a platform positioned in a zero-turning-radiusmower such that the operator is substantially unaffected by centrifugalforce created during approximate zero-radius turns, thereby allowing theoperator/mower to take such turns at higher speeds; (v) a platformpositioned in a manner such that the mower is less likely to popwheelies upon acceleration; etc. Each of the above advantages isaccomplished by positioning the standing-operator platform of the mowersubstantially between the rear drive wheels.

It is the purpose of this invention to fulfill the above-described needsin the art, as well as other needs which will become apparent to theskilled artisan from the following detailed description of thisinvention.

SUMMARY OF THE INVENTION

Generally speaking, this invention fulfills the above-described needs inthe art by providing a zero-turning-radius power mower for operation bya standing-occupant, comprising:

an engine;

at least one cutting member powered by the engine;

first and second rear drive wheels each independently driveable in bothforward and reverse directions so as to allow for substantiallyzero-radius turning of the mower about a turning point when the reardrive wheels are driven in a predetermined manner; and

a riding platform for supporting the standing-occupant, the ridingplatform being located substantially at the turning point so that thestanding-occupant is substantially unaffected by centrifugal forcecreated during zero-radius-turning of the mower.

This invention further fulfills the above-described needs in the art byproviding a power mower for operation by a standing-occupant,comprising:

an engine for driving a cutting member;

first and second rear drive wheels each rotatable about a common axis;

a riding platform fixedly mounted on the mower for supporting thestanding-occupant, the platform being located between the first andsecond rear drive wheels during operation of the mower so that when thestanding-occupant stands on the platform the standing-occupant isbetween the first and second rear drive wheels along the axis, wherebythe platform is less susceptible to impacting the ground when going overbumps and the like.

This invention will now be described with respect to certain embodimentsthereof, accompanied by certain illustrations, wherein:

IN THE DRAWINGS

FIG. 1 is a top view of a zero-turning-radius power lawn mower accordingto certain embodiments of this invention.

FIG. 2 is a side elevational view of the power mower of FIG. 1 accordingto certain embodiments of this invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THIS INVENTION

Referring now more particularly to the accompanying drawings in whichlike reference numerals indicate like parts throughout the severalviews.

FIGS. 1 and 2 are top and side views respectively of power lawn mower 1according to a first embodiment of this invention. Power lawn mower 1includes cutter assembly 3 and drive assembly 5.

Cutter assembly 3 includes engine 7 and cutter or mower deck 9. Mowerdeck 9 is mounted on and below frame 11 in front of engine 7 and enginedeck 13. Mower deck 9 is positioned close to the ground below enginedeck 13, engine 7, and frame 11 in certain embodiments of thisinvention. In the first embodiment as shown in FIG. 2, mower deck 9 ismounted on and connected to both engine deck 13 and frame 11. Frame 11includes a pair of substantially parallel frame members which extendlongitudinally along mower 1. Mower deck 9 (or alternatively the mowerwheels) is vertically moveable or adjustable so as to adjust the heightof the cut. Deck 9 may be about 36-72 inches wide according to certainembodiments.

Mounted below mower deck 9 is one or more (e.g. three) cutting membersor blades 15 which rotate in a horizontal plane on vertical shaft(s) 17which are coupled to engine 7 by way of a belt drive assembly includingbelts 19 and 21. Three cutting blades 15 and corresponding shafts 17 areprovided in the first embodiment. Alternatively, as few as one blade 15and as many as five blades 15 may be provided in certain otherembodiments of this invention.

As shown in FIG. 1, drive belt 21 is coupled between the centralvertical shaft 17 and engine 7. Secondary blade belts 19 are connectedbetween the central vertical shaft 17 and the two peripheral shafts 17respectively. Thus, belts 19 are driven as a result of central shaft 17being driven by belt 21 which is coupled to and powered by engine 7.Cutter assembly 3 and its associated drive and engine 7 are conventionalin nature and therefore will not be discussed in further detail.

Drive assembly 5 includes engine deck 13 for supporting conventionalgasoline engine 7 (e.g. 2 cylinder, 22 HP, V-twin), rear drive wheels 23and 25, hydraulic pumps 31 and 33, motors 27 and 29, etc. Each drivewheel assembly includes a protective fender 24. First and second reardrive wheels 23 and 25 are mounted either directly or indirectly onmower frame 11 and are generally disposed on opposite sides of engine 7.Hydrostatic drive wheel motors 27 and 29 are mounted on mower 1 so as todrive wheels 23 and 25 respectively. Hydrostatic pumps 31 and 33 aremounted on either engine deck 13 or frame 11 as shown. Hydrostatic pump31 is in communication with motor 27 and left rear drive wheel 23 whilehydrostatic pump 33 communicates with hydrostatic motor 29 and rightrear drive wheel 25.

Each rear drive wheel 23 and 25 is mounted on its own drive axle 28 incertain embodiments of this invention. Axle 28 for wheel 23 may be partof motor 27 or alternatively may be separate from motor 27. The same istrue for axle 28 upon which rear wheel 25 is mounted. In certain otherembodiments of this invention, both rear drive wheels 23 and 25 may bemounted on a single supporting axle.

Hydrostatic pumps 31 and 33 are in conventional communication withhydrostatic motors 27 and 29 by way of, for example, a plurality ofhydraulic fluid hoses 6 and 8 disposed between each pump andcorresponding motor. Pumps 31 and 33 including known swash plates (notshown) and generate hydraulic fluid pressure which is translated throughone of two hoses 6 and 8 connecting each pump (31 or 33) to its motor(27 or 29). Hydraulic hoses 6 and 8 are coupled between each pump (31and 33) and its motor (27 and 29) so as to allow hydraulic fluid to flowin both directions between each pump and its motor. One hydraulic hose(6 or 8) is for allowing hydraulic fluid to flow in one direction andthe other hose is for permitting the fluid to flow in the oppositedirection.

For example, when fluid flows from pump 33 (or 31) to right drive wheelmotor 29 (or 27) via hose 6 and back to pump 33 through hose 8 thenmotor 29 and wheel 25 are driven in the forward direction. The speed atwhich wheel 25 is driven depends upon the rate of flow. However, whenthe fluid flow is reversed so that the fluid flows to motor 29 throughhose 8 and back to pump 33 through hose 6, then motor 29 and wheel 25are driven in the reverse direction.

Hydrostatic pumps 31 and 33 are driven by engine 7 by way of belts 35.Each pump 31 and 33 includes a conventional pump control lever (notshown) extending therefrom for permitting the standing-operator tocontrol the speed and forward/reverse sense of each rear drive wheel viaa lever 53 provided on the handle 39 of mower 1.

Alternatively, motors 27 and 29 could be positioned on frame 11 or deck13 adjacent engine 7 so that rear drive wheels 23 and 25 could insteadbe driven by chains in a known manner.

Front caster wheels 41 are mounted at the front of mower deck 9 or frame11 by way of conventional caster assemblies 43. Each caster assembly 43includes caster pivot 45 and caster support 47. Caster assemblies 43allow mower 1 to be turned in any and all directions by rear drivewheels 23 and 25 as will be discussed more fully below.

Upwardly extending handles are provided for handling and manipulatingmower 1 and include a pair of handle members 39 and optionally a crossmember (not shown) secured between handle members 39 to hold themstructurally substantially parallel to one another in a spaced apartmanner. Each handle member 39 is connected to either frame 11 or mowerdeck 9 by way of bolts, screws, welds, or any other conventionalconnectors. Handle members 39 extend upwardly and slightly rearwardlytoward the standing-operator but located forward of the turning axis orthe central point 61, as clearly seen in FIG. 2, according to certainembodiments of this invention so as to allow the operator to griphandles 39 and thereby control mower 1 via various controls (all ofwhich are not shown) mounted on handles 39.

Speed and turning control assembly 51 is attached to handle members 39near the gripping portions thereof and includes speed control levers 53connected to each handle 39. Each speed control lever 53 which ispivotally mounted on a handle member 39 is conventionally coupled to oneof pumps 31 or 33 by way of their control lever (not shown) so that thelever 53 mounted on left handle 39 is coupled to left pump 31 andcontrols the speed of left rear drive wheel 23 and the other lever 53which is mounted on right handle 39 controls the speed of right reardrive wheel 25 via right hydrostatic pump 33 and motor 29.

The direction (forward/reverse) that each drive wheel 23 and 25 isdriven is also conventionally controlled by the standing-operator viacontrol levers mounted on handles 39. Speed control levers 53 may alsobe used to control the direction or, alternatively, different levers 54can be coupled to pumps 31 and 33 for controlling direction in a knownmanner.

In operation, when engine 7 is running, hydrostatic pumps 31 and 33 aredriven at substantially the same speed. Hydraulic fluid under pressureis variably delivered to wheel motors 27 and 29 through first and secondconduits 6 and 8 extending between each pump and its respective motor.When the direction of fluid flow is to the motor is through the firstconduit 6 and return flow to the pump through the second conduit 8, themotor (27 or 29) is driven in the forward direction so that itsrespective drive wheel (23 or 25) is also driven in the forwarddirection. On the other hand, when the fluid flow is in the oppositedirection (i.e. going from the pump to the motor through the secondconduit 8 and returning to the pump through the first conduit 6) thiswill cause the motor to operate in the reverse direction so as to causeits respective drive wheel to be driven rearwardly. Whether or not drivewheels 23 and 25 are driven in either the forward or rearward directionis determined by the position of the above discussed control leversmounted on each handle member 39.

In such a manner, the standing-operator may conventionally manipulatethe control levers so as to cause rear drive wheels 23 and 25 to either:(i) both be driven in the forward direction; (ii) both be driven in therearward direction; or (iii) one be driven in the forward direction withthe other being driven in the rearward direction.

In certain embodiments of this invention, a 1-2 gallon hydraulic fluidreservoir (not shown) for pumps 31 and 33 is mounted on and betweenhandle members 39 substantially above pumps 31 and 33. Conventionalclutch and brake levers (not shown) may also be mounted on handles 39 incertain embodiments of this invention.

Turning of mower 1 is carried out in one of three ways. Firstly, thestanding-operator can cause mower 1 to turn in either direction bystopping one of the two rear drive wheels 23 and 25 (e.g. via clutch orbrake) while allowing the other to continue to be driven in either theforward or reverse direction. This may be carried out via theconventional handle 39 mounted control levers. Secondly, thestanding-operator can cause the mower to turn by allowing drive wheels23 and 25 to be driven in the same direction (forward or reverse), butat different speeds. Thirdly, the operator can turn mower 1 by causingrear drive wheel 23 to be driven in one direction and the other drivewheel 25 to be driven in the opposite direction.

When rear drive wheels 23 and 25 are driven in opposite directions atsubstantially similar speeds, substantial zero-radius-turning isaccomplished about center point 61 of circle 63. In zero-radius-turning,mower 1 turns either leftwardly or rightwardly (depending upon whichdrive wheel is being driven forward) about central point 61. Thus,circle 63, as illustrated, shows the path along which the front portionof mower 1 proceeds during substantial zero-radius-turning. Duringsubstantial zero-radius-turning of mower 1, central point 61 of circle63 is positioned along or near the rear drive wheel axis as shown inFIGS. 1 and 2. Accordingly, what is meant by "zero-radius-turning" isthat mower 1 turns about a point 61 disposed between the drive wheels,and that point 61 does not move to any great extent during the turning.

Platform 71 for supporting the standing-operator or occupant is disposedbetween rear drive wheels 23 and 25 along rear drive wheel axis 81 whichis defined by the rear drive wheel's axes of rotation. By positioningstanding platform 71 between rear drive wheels 23 and 25 substantiallyalong drive wheel axis 81 so as to include central point 61, thestanding-operator is substantially unaffected by centrifugal forcecreated during approximate zero-radius-turning of mower 1.

For example, if during a substantially zero-radius-turn of mower 1, theoperator was positioned at a location distant from central point 61(e.g. along the front of mower deck 9 or far rearward of wheels 23 and25, for example) then he would be adversely affected by centrifugalforce created during the turn in that the operator would be pushed awayfrom point 61 by the centrifugal force. However, when thestanding-operator is located at or very near central point 61 due to theposition of standing platform 71, he is substantially unaffected by suchcentrifugal force and therefore can operate mower 1 so as to take suchapproximate zero-radius turns at higher speeds. Furthermore, bypositioning the standing-operator on substantially flat platform 71 inclose proximity to central point 61, the operator is less affected bycentrifugal force created during other (non-zero-radius) turnsundertaken by mower 1. The less the operator is affected by suchcentrifugal force, the less fatigued he becomes and the higher speeds hemay allow or cause mower 1 to take such turns.

Standing platform 71, as illustrated in FIG. 2, is positioned below reardrive wheel axis 81 thereby enabling the standing-operator to locate hisweight near the ground during normal mower operations thus resulting inan effective mower center of gravity which is also close to the ground.This position of platform 71 allows the standing-operator's weight to befocused at a point below rear drive axis 81 during typical operations ofmower 1 according to certain embodiments. In side hill environments, theoperator is thus permitted to shift his weight in order to compensatefor tipping tendencies. The resulting low center of gravity rendersmower 1 safer in that it is less susceptible to tipping or rolling,especially in hilly environments. Furthermore, this low center ofgravity focused along rear drive wheel axis 81 creates improved tractionof rear drive wheels 23 and 25, especially during side hill mowingoperations.

Platform 71 is surrounded or defined on its wheel sides by sidewalls 87and on its engine or front side by wall 89. Motors 27 and 29 are atleast partially encased behind sidewalls 87 and within compartments 88defined thereby. Alternatively, motors 27 and 29 may be fully encasedwithin compartments 88. Sidewalls 87 and 89 which define platform 71protect the operator's feet and lower legs from hazards associated withengine 7, motors 27, 29, blades 15, etc. while bottom wall 91 ofplatform 71 protects the operator from hazards beneath the mower such asblades 15 and flying debris.

The tops of sidewalls 87 define flat supports 93 upon which thestanding-operator may position his feet when he needs to increase theweight or improve the traction of one of the rear drive wheels. This isespecially helpful in side hill environments when improved traction isoften required on the top (or highest) rear drive wheel (25 or 23).Because the operator is standing on platform 71, he can easily shift hisweight to a side of the machine needing either additional tire tractionor additional weight for counterbalancing tipping.

Another advantage associated with the positioning of standing platform71 between rear drive wheels 23 and 25 is that platform 71 is unlikelyto bottom out or contact the ground when mower 1 goes over bumps, curbs,and the like. If, for example, platform 71 were located well behind reardrive wheels 23 and 25 as in the prior art, it would significantlyincrease the likelihood of the platform bottoming out as the mowertraveled in a forward direction over a curb or other similar bump.However, positioning platform 71 between the rear drive wheels and alongrear drive wheel axis 81 in certain embodiments of this inventioncreates a situation where the possibility of standing-operator platform71 bottoming out as the mower goes over bumps, curbs, and the like isvirtually eliminated.

The positioning of platform 71 between rear drive wheels 23 and 25 alongrear drive wheel axis 81 also results in mower 1 being less susceptibleto popping wheelies when the mower is accelerated, especially when goingup hills. This is because the positioning of the standing-operator'sweight along rear drive wheel axis 81 (as opposed to at a locationbehind the rear drive wheels) results in the mower's center of gravitybeing closer to the front of the mower thereby resulting in it beingless likely to pop wheelies upon acceleration.

It is noted at this point that in the prior art, burdensomecounterweights (not shown) often had to be affixed to the front ofwalk-behind power mowers in order to move the mower's center of gravityforward so that the mower would not pop wheelies upon acceleration.

Yet another advantage of platform 71 being disposed between rear drivewheels 23 and 25 (as opposed to at a position rearwardly thereof) isthat there is no longer a need for disposing such counterweights alongthe front of the mower. This is because the operator's weight is locatedsubstantially along the rear drive wheel axis, and not at some positionrearwardly thereof which requires the positioning of counterweights onthe front of the mower. Accordingly, the position of platform 71 alsoallows engine 7 to be located more rearwardly than in the prior art,thus resulting in a larger mower deck 9 and more room for repairs andother such needs.

Mower 1, as described above, has a reduced overall length with respectto certain prior art mowers as a result of platform 71 being locatedbetween rear drive wheels 23 and 25 (as opposed to rearwardly thereof).This allows the mower to be more easily and efficiently operated intight locations and, in fact, permits mower 1 to access regionspreviously unaccessible. The shorter overall length of mower 1 alsoallows for more compact storage and transport. Furthermore, by allowingthe standing-operator to be between the rear wheels, the operator isless likely to impact obstacles such as trees and the like during moweroperations in tight environments such as woods, heavy brush, etc.

While certain preferred embodiments of this invention involve power lawnmowers, the standing-operator platform of this invention may also beplaced between the rear drive wheels of other power driven devices suchas soil or lawn aerators, or other powered lawn maintenance devices.

According to certain alternative embodiments, a operator seat could bepositioned at point 61 so as to make the mower a seated-operator typemower.

Once given the above disclosure, therefore, various other modifications,features, or improvements will become apparent to the skilled artisan.Such other features, modifications, and improvements are thus considereda part of this invention, the scope of which is to be determined by thefollowing claims.

We claim:
 1. A zero-turning radius self-propelled power mower foroperation by a standing occupant, the self-propelled power mowercomprising:a cutting member; an engine for powering said cutting member;first and second rear drive wheels each independently driveable inforward and reverse directions so as to allow for substantiallyzero-radius turning of the mower about a turning axis when said reardrive wheels are driven in a predetermined manner; a handle memberincluding a hand grip portion, said hand grip portion located forward ofsaid turning axis so that hands of the standing occupant may be normallylocated forward of said turning axis during zero-radius-turns of themower; a foot platform for supporting feet of the standing occupant,said foot platform located at a position relative to said hand gripportion so that a substantial portion of the standing occupant's bodymay be located substantially on said turning axis during approximatezero-radius-turns of the mower and thus be substantially unaffected bycentrifugal force created during approximate zero-radius-turns of themower; and wherein a substantial portion of said foot platform islocated at an elevation below or substantially near an axis of at leastone of said rear drive wheels so as to create a low center of gravity.2. The mower of claim 1, further comprising two additional cuttingmembers driven by said engine, and hydraulic or hydrostatic means fordriving said rear drive wheels.
 3. A zero-turning radius self-propelledpower mower for operation by a standing occupant, the zero-turningradius self-propelled power mower comprising:an engine; at least onecutting member powered by said engine; first and second rear drivewheels each independently driveable in both forward and reversedirections so as to allow for substantially zero-radius turning of themower about a turning axis when said rear drive wheels are driven in apredetermined manner; a first hydrostatically powered means connected tosaid first rear drive wheel and a second hydrostatically powered meansconnected to said second rear drive wheel, said first and secondhydrostatically powered means being positioned and oriented so that saidfirst and second hydrostatically powered means drive said first andsecond rear drive wheels, respectively; a mower deck for housing said atleast one cutting member, at least a substantial portion of said mowerdeck and said cutting member being located substantially forward of saidfirst and second rear drive wheels; a handle member including a handgrip portion, said hand grip portion being located forward of saidturning axis so that hands of the standing occupant are normally locatedforward of said turning axis during zero-radius turns of the mower; afoot platform for supporting the standing occupant, wherein said footplatform is located at a position relative to said hand grip portion sothat at least a portion of the standing occupant's body is locatedsubstantially on said turning axis during zero-radius turns of the mowerso that the standing occupant is substantially unaffected by centrifugalforce created during zero-radius turns of the mower; and wherein aportion of said foot platform is located below the tops of said reardrive wheels so as to create a low center of gravity of the mower.
 4. Azero-turning radius self-propelled power mower operable by a standingoccupant, the zero-turning radius power mower comprising:an engine fordriving a cutting blade; said cutting blade being mounted under acutting deck and being powered by said engine; first and second reardrive wheels each independently driveable in both forward and reversedirections so as to allow for substantially zero-radius turning of themower about a turning axis; a first hydrostatically powered motor drivenby a first hydraulic pump, said first hydrostatically powered motorconnected to said first drive wheel, and a second hydrostaticallypowered motor driven by a second hydraulic pump, said secondhydrostatically powered motor connected to said second drive wheel, saidfirst and second hydrostatically powered motors being positioned andoriented so as to drive said first and second drive wheels,respectively; said cutting deck for housing at least said cutting blade,at least a portion of said deck being located forward of said first andsecond drive wheels; a handle member including a hand grip portion, saidhand grip portion being locatable forward of said turning axis so thatwhen said hand grip portion is located in such a manner hands of thestanding occupant when gripping said hand grip portion are normallylocated forward of said turning axis during turns of the mower in orderto allow centrifugal force upon the occupant to be minimized; a footplatform for supporting the standing occupant, wherein said footplatform is located at a position relative to said hand grip portion sothat at least a portion of the standing occupant's body may be locatedsubstantially on said turning axis during turns of the mower so that theeffect of centrifugal force on the standing occupant is minimized duringzero radius turns of the mower; wherein a portion of said foot platformis located below the tops of said rear drive wheels so as to create alow center of gravity of the mower; and an engine deck upon which theengine is mounted, the engine deck defining a plane at a top surface ofsaid engine deck, said engine deck being at least partially located atan elevation above a portion of said cutting deck; said foot platformbeing located at an elevation substantially below an elevation of saidplane of said engine deck during operation of the mower when thestanding occupant is on said foot platform, and said foot platform beingpositioned so that feet of the standing occupant can be positioned at anelevation below the elevation of said plane of said engine deck duringmower operation.